There is a natural tendency for all programming languages to want to both retain backwards compatibility and also accumulate new features, eventually outgrowing

There is a natural tendency for all programming languages to want to both retain backwards compatibility and also accumulate new features, eventually outgrowing the original design. C++ is obviously well past this point. If this was a code base rather than a language specification, then this would be the time to refactor, but with a programming language you've got a world full of code, compilers and tools, and the resistance to change is massive. One of the few success stories of a language refactoring and dropping backwards compatibility is Python 2 -> Python 3 (a 10+ year struggle). What might be considered as a failure case is Perl 5 -> Perl 6, where resistance to change caused the migration to Perl 6 to be so slow that effectively Perl 5 won, and the language itself became obsolete. So, be careful for what you wish for - C++ certainly needs a refactoring, but whether it could survive it is another question, especially now since backwards compatibility is what is keeping it alive in the face of competition, and it's not at all clear going forwards what the impact of AI on programming languages is going to be.